package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.FOLLOWS_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Autowired
    private FollowMapper followMapper;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private IUserService userService;

    /**
     * 关注或取关
     * @param followUserId
     * @param isFollow
     * @return
     */
    @Override
    public Result follow(Long followUserId, Boolean isFollow) {

        // 获取登录的用户id
        Long userId = UserHolder.getUser().getId();

        String key= FOLLOWS_KEY +userId;

        //1.判断是关注还是取关
        if (isFollow){
            //2.关注，新增
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSuccess = save(follow);
            if (isSuccess){
                //把关注用户的id,放入redis的set集合 sadd userId followUserId
                stringRedisTemplate.opsForSet().add(key,followUserId.toString());
            }
        }else {
            //3.取关，删除
            boolean isSuccess = followMapper.deleteById(userId, followUserId);
            if (isSuccess){
                //把关注的用户id从redis集合中移除
                stringRedisTemplate.opsForSet().remove(key,followUserId.toString());
            }

        }

        return Result.ok();
    }

    /**
     * 判断是否关注
     * @param followUserId
     * @return
     */
    @Override
    public Result isFollow(Long followUserId) {

        //获取当前用户id
        Long userId = UserHolder.getUser().getId();

        //1.查询是否关注
        Integer count = query().eq("follow_user_id", followUserId).eq("user_id", userId).count();

        return Result.ok(count > 0);
    }

    @Override
    public Result followCommons(Long id) {

        //1. 获取当前用户
        Long userId = UserHolder.getUser().getId();
        String key=FOLLOWS_KEY+userId;
        String key2 =FOLLOWS_KEY+id;

        //2.求交集
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key, key2);

        if (intersect == null || intersect.isEmpty()){
            return Result.ok(Collections.emptyList());
        }

        //解析出id ,查询用户
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());

        List<UserDTO> users = userService.listByIds(ids)
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());

        return Result.ok(users);
    }
}
